To provide a neurophysiological basis for visual perception of movement, it was proposed to study the behavior of single neurons in the visual cortex of the monkey during eye movements. Visual detection of movement depends on two sources of information: a sensory and a sensorimotor process. The former is derived from the shift of retinal images-occurring in the stationary eyes. The latter is related to the movement signals during eye movements. In this case, the speed of a moving object is determined by the angular velocity of the tracking eye movement, where the image of the object falls on the same spot in the moving fovea. This type of movement detection would depend on the oculomotor information which is conveyed to the visual system corollary of the activation of extraocular muscles (corollary discharge hypothesis). Suppose a corollary discharge existed, a cell would be coded with temporal information about an impending eye movement. Some cells would be coded specifically with a direction, amplitude or speed of eye movement or instantaneous position of the eyes. Keeping these assumptions in mind, the unit activity will be correlated with temporal relation to eye movement and spatial relation to eye position. BIBLIOGRAPHIC REFERENCES: Noda, H. 1975. Sustained and transient discharges of retinal ganglion cells during spontaneous eye movements of cats. Brain Res. 84, 515-529. Noda, H. and Iwama, K. 1975. Behavior of cortical neurons during both sleep and barbiturate anesthesia. Ed. K. Mori. In: The Effect of Anesthetics in the Central Nervous System. Little Brown: Boston. pp. 37-66.